1. Field of the Invention
The present invention relates to a rotary grinding jig for use with the rotating shaft of a rotary drive of a grinder and the like having driving mechanisms of various sorts, in an arrangement such that the rotary grinding jig is firmly secured to said rotating shaft.
2. Description of Related Art
FIG. 22 is a central sectional view explanatory of conventional rotary grinding jigs of a same type, (A) showing the one before use, and (B) the other one with a worn-out grinding member after use.
This prior art rotary grinding jig comprises a disk-shaped base 100 made of resin or metal and a grinding member 200 stuck to the surface 101 of said base by adhesive.
The grinding member 200 is composed of a plurality of substantially rectangular grinding cloths 201, . . . 201 overlapped with each other in a radial arrangement.
Said rotary grinding jig can be fixed to the rotary shaft of the grinder by inserting a rotary shaft of the grinder (not shown), having a male screw portion formed on the end thereof from below upward into a rotating shaft mounting hole 102 formed in the center of the base, mounting a nut onto the male screw portion of the rotating shaft, and tightening said nut by a clamping tool.
If the grinding member 200 has work out, the whole rotary grinding member will be thrown away together with the base 100, as shown in FIG. 22(B).
Though not shown here, there exists a rotary grinding jig wherein the base and the grinding member are in close but removable contact with each other by an area fastener.
As aforementioned, with the conventional rotary grinding jig having the grinding member 200 adhered to the base 100 made of resin or metal, if the grinding member 200 has entirely worn out, the entire grinding jig must be discarded.
However, considering that the whole grinding jig must be discarded together with the base, it is a concern that this may greatly affect the environment. In addition, discarding the entire grinding jig is also not preferable in view of the saving in resources,. Furthermore, the material cost is also not negligible for manufacturers.
In case of the exchange of the rotary grinding jig, a spent grinding jig is removed from the rotating shaft of the grinder by loosening the nut by a tool, and then, a new grinding jig is mounted onto the rotating shaft of the grinder, the rotating shaft is tightened using the tool again for further fixing the grinding jig thereto. This takes a great deal of trouble and the workability as well as the working efficiency are very low. On the other hand, there lies a big problem in that with the grinding member and the base removably fixed to each other by an area fastener, the mounting strength or fixing strength is poor.
In this connection, the present invention has for its object the resolution of the above-described problem and for its task the following matters.
The rotary grinding jig must be so designed that if the grinding member has uselessly worn out, waste portions of the rotary grinding jig may be reduced to a minimum. This may reduce industrial wastes, avoid any adverse influence against the environment, contribute to saving energy, and lead to a cut in production cost as well.
A worn-out and useless rotary grinding jig must be exchanged for a new one by a very simple one-touch control. This may execute the exchange of the grinding jig simply and in a short time, thus resulting in improvement of the workability and working efficiency.
Such a one-touch control system for exchange of the grinding jig must not cause any loss of mounting strength for the grinding jig. The removable fixing by the conventional area fastener cannot assure a sufficient mounting strength, therefore, additional fixing means such as screws for maintaining the strength was used.
Moreover, there must be provided a means for preventing the grinding jig which has been mounted by a one-touch control from simply coming off its position. That is, a means must be provided for preventing any dissolution of the engagement achieved by such a one-touch control and any possible dropout of the grinding member or retaining member for the grinding member of the rotary grinding jig even though the rotary drive of a grinder has stopped all of a sudden.
Additionally, a further task of the present invention is to provide a rotary grinding jig which may be produced by using every type of grinding member, such as a grindstone, integral structure of a grindstone and resin, abrasive paper, feather cloth, rubber, etc.